Air preheater



Oct. 4, 1932. H. H. Dow l-:T Al. 1,880,196

AIR- PREHEATER Filed July 6, 1925 2 Sheets-Sheet l COLD AIE IN lb i 'l' /5v 1 MN NN 2 5.h-- i f M ma l il l 9 7 lab j oct. 4, 1932. H. H. Dow Er AL 1,880,196

AIR PREHEATER Filed Julie, 1925 2 sheets-sheet 2 l N V EN TOR A TTORNEY Patented Oct. 4, 1932 UNITED STATES i PATENT ortica y HERBERT H. DOW AND GUY H. CANNON,

OF MIDLAND, MICHIGAN, ASSIG-NORS, :BYV

N. VY., A CORPORATION or New Your:

AIR PREHEATER Application led July 6,

One particular field of use for the present improved' air preheater is as an apparatus for utilizing the hot flue gases from a furl nace to heat the air required in the combus- 4`tion of the Vfuel used in such furnace. it

will be understood, however, that such apparatus may be employed in various other fields where it is desired to interchange heathetween two fluid mecha.

The following may be enumerated as objects of the invention, viz:

To utilize the heat of stack gases in an apparatus that will not be rendered inoperative by the corrosive fumes contained in said 4 gases.

To provide a simple and compact mecha nism for the purpose stated and one that will not require any great amount of power for its operation.

To use any heat absorbing material, irrespective of whether it be uniform in size,

----cleaning will remove the shape or kind, or how it be arranged in cham? bers. To obtain a long life for the preheater, be-,

` cause corrosion or disintegrationof the heat absorbing material will not destroy the usefulness of the preheater. If the disintegrating particles collect and tendV to obstruct the flow'of the media through the packing, a small particles and the larger material may be used over again.

To obtain a high rate of heat transfer between the heat absorbing material andthe Amedia through turbulence and good scrub-A -bing action caused by the irregular paththat the media has to take while owing through the heat absorbing material.

To obtain a continuous transfer of heat from the hot media to the heat absorbing'ma- 'terial, simultaneously with heat beingftransferred from the heat radiating material to the cold madia through the use of a plurality of chambers.

To have a minimum numberv of chambers necessarily out of communication with either the hot or cold media at any one time by the use of an odd plurality of chambers.

To shape the rotating valves so that end play in the driving shaft from expansion or wear `in the step bearing will not affect the 1925.Y serial No. 41,565.

clearance between the valves and theports into the plurality of chambers, thereby preventing the contamination of the two media one withthe other.

To the accomplishment of the foregoing and related ends, the invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims', the yannexeddrawings and the following description setting forth in detail certain mechanism embodying the invention, such disclosed :meansL constituting, however, but one of various mechanical forms in which .the principle of the invention-may be used.

In said annexed drawings?- Fig. l is a central vertical section on the line l-1 of Fig.y 5 through an air preheating apparatus embodying the ypresent .improvements'; ,F ig. 2 is a. top plan view thereof; and Fig. 3 is a transverse section of the same, taken on the plane indicated by the line 3-3, Fig. l; Fig. 4t is a perspective view of one of the valve cages, andFg. 5 tion therethrough.

The body of such illustrative apparatus comprises an odd plurality of circularly arranged chambers or compartments l, formed by an outercylindrical shell 2', anV inner shell 3 concentric therewith, and the proper number of radialfpartitions. Such inner shell' terminates short of the respective ends L and 5 of the outer shelland is connected with such ends by means vof similar valve cages 6 and 7, whichl are open laterally to provide for the free inowl or outflow of gases, as the case may be, to orl from the compartments or chambers l. Such valve cages atl the same time constitute 'a simple construction for insuring a good joint between the respective the inner shell 3 where the latter is'connected with the lower valve cage 7. This grid serves to support suitable heat absorbing packing is a horizontal seca grid 8- is provided Sii material' which substantially fills 'each compartment, this material, as shown, consisting of a plurality of short iron rings 9 placed end upon end but in staggered relation so that the air or gas in traveling through the compartments necessarily has to follow a tortuous course. The radial partitions 10 whereby the annularspace between shells 2 and 3 is subdivided into such plurality of longitudinally extending compartments are best shown in Fig, 3, it being understood that the aforesaid filling material is packed between these partitions. f

Mounted in the respective valve cages 6 and 7 are rotary valves 12 and 13, respectively, that are identical except that they project in opposite directions. Each valve, in other words, consists of a plate-like base 12a and 13a u on which the valve ro er is mounted a P i section 12e which is equipped with a depend* ing skirt 12f forming the upper boundary of the port opening 12b. The valves are hired upon a common centralv shaft 15 that is journaled in suitable axially aligned bearings lr6 within the shell 3. ()ne end of said shaft, the upper as shown, projects beyond the correspondingend of the apparatus and has secured thereto a. beveledgear 17 whereby the a predetermined rate. A

The cylindrical body portion of the lower valve 13 has a close moving tit within a sleeve 2O which forms in eiiect one endv of a duct 40 -`21 through which hot Prue gas is supplied to the apparatus; wliile the body of the upper valve 12 similarly lits within a sleeve 22 that forms in elfect one end of a duct 23 through which the flue gases escape to thestack or 'chimney afterpassing through the'apparatus.

The annular space between sleeve and the.

valve cage 7 is connected Vwith achamber or duct 24 through which theair, after it has Vpassed throughthe apparatus, is led to the while similarly connected with the annular space between sleeve 22 and valve cage 6 is a duct 25 through which the cold air is led into the apparatus. Ventilating fans 26 and 27, mounted on a common powerdriven shaft 28, are located in such duct 25, through which thecold air is thus admitted, and in duct 23, through which the uefgases are discharged .to the stack, respectively, so as'to `force the iow of such air and gases to whatever extent may be necessary. l y

In operation, as the vertical shaft 15 rotates, the hot flue gases enteringby way of .duct 21 are caused to pass through port 13b in valve 13 intosuccessive vertical comparu plates 12d merging with the annular plate shaft with attached valves may be rotated at i combination of inner and outer concentric shells forming an annular chamber; radial furnace or other point where it is to be used ;1

ment-s 1 in the annular space between shellsk air entering the chambers 1 through duct 25 i and the annular space between sleeve 22 and valve cage 6. 'After' becoming thus heated,

the air is discharged from thev chambers 1 through the annular space between the sleeve 20V and valve cage 7 into duct 24.

The. form of the valve bodies 12 and 13 is Y such that the compartment or compartments or chambers 1, through which the hot flue gas is beingV conducted, will be completely kshut on against passage ofv the air therethrough i and commingling of the latter with the fluel gas accordingly prevented. VIt will also be understood that the length of chambers 1 may be varied to suit the requirements of thek 'particular installation, the longer the path of travel of the hot gas and cold air, the more complete the heat interchange therebetween.

Other modes of applying the principle of 'l 'our invention may be employed instead of the one explained, change being made as regards the mechanism herein. disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed` I Ne therefore particularly point out and kdistinctly claim as our invention 1. 4In a heat interchange apparatus, the

partitions dividing said chamber into a plu# ralityof circularly arranged compartments, the latter containing heat absorbent material adapted to -permit a fluid medium to pass therethrough; a valve cage 'at each end of said inner. shell adapted toV communicate.'

freely with saidcompaitments; an inlet duct leading to and an exit duct from each of said valvecages; and a rotary valve-in each of the latter adapted to` place i said compartments:V successively in communication with the inletduct at onefend andrwith the outlet duct at the other, andto place the remaining :compartments similarly in communication` with the other pair of ducts. n

2. In a heat interchange apparatus, the

combination of inner4 and outer concentric shells forming an annularchamber; radial partitions dividing said chamber into a plus rality of circularly arranged compartments,A the latter containing heat absorbent material adapted to permit a. iud medium to pass therethrough; a valve cageat each end of said inner shell adapted to communicate freely with said compartments; an inlet duct leading to and an eXit duct from each of said valve cages; a, rotary valve in each of the: latter. ladapted to. place. said compartments said successively in communication With the inlet duct at one end and With the outlet duct at the other, and to place the remaining compartments similarly in communication With the other pair of ducts; and a shaft disposed centrally 'Within said inner shell, Whereon said valves are mounted for rotation in unison.

3. In a heat interchange apparatus, the combination of inner and outer concentric shells forming an annular chamber; radial partitions dividing said chamber into a. plurality of circularly arranged compartments, the latter containing heat absorbent material adapted to permit a liuid medium to pass therethrough; a valve cage at each end of said inner shell adapted to communicate freely With said compartments; an inlet duct leading to and an exit duct from each of said valve cages; and a rotary valve in each of the latter adapted to place said compartments successively in communication With the inlet duct at one end and With the outlet duct at the other, and to place the remaining compartments similarly in communication with the other pair of ducts, each of said valves comprising. a circular base closing the corresponding end of said inner shell and a cylindrical portion rising from such base and provided With a ported offset portion whereby communication between the interior of said valve and the compartments in said annular chamber is limited to a deiinite number of such compartments at any one time.

4. In a heat interchange apparatus, the combination of inner and outer concentric shells forming an annular chamber; radial partitions dividing said chamber into a plurality of circularly arranged compartments, the latter containing heat absorbent material adapted to permit a fluid medium to pass therethrough; a valve cage at each end of inner shell adapted to communicate freely with said compartments; an inlet duct leading to and an exit duct from each of said valve cages, one such inlet duct and the corresponding exit duct being aligned transversely of the axis of said chamber; a shaft extending centrally of said ducts; ventilating fans mounted on said shaft in each of said chiots; a rotary valve 1n each of said valve cages adapted to place said compartments successively in communication With the inlet duct at one end and with the outlet duct at the other, and to place the remaining compartments similarly in communication with the other pair of ducts.

5. In a heat exchange apparatus, an annular chamber containing regenerative material having passages extending therethrough,

Va supply channel and a discharge channel for a iiuid to be heated, a supply channel and a discharge channel for a fluid to be cooled, and valve mechanism for controlling flow of one fluid through'selected passages' and flow of the other fluid through other passages, and means -for moving said valve mechanism.

6. Ina heat exchange apparatus, an annular chamber containing regenerative material having' passages extending therethrough, a supply channel and a discharge channel for a fluid to be heated, a supply channel and a discharge channel for a fluid to, be cooled, and valve mechanism for controlling flow of one fluid through 'selected passages and flow of the other fluid through other passages, forA rotating and valve'mechanism.

7. In aheat exchange-apparatus, an annular chamber containing compartments, each compartment having regenerative material having pasages extending therethrough, a supply channel and a discharge channel for a fluid to be heated, a supply channel and a discharge channel for a luidto be cooled, and valve mechanism for controlling flow of one fluid through selected compartments and flow of the other liuid through other compartments, and means for moving said valve mechanism.

8. In a heat exchange apparatus, an annular chamber containing compartments, each compartment having regenerative material having passages extending therethrough, a supply channel and a discharge channel for a fluid to be heated, a supply channel and a discharge channel for a duid to be cooled, and valve mechanism for controlling iioW of one fluid through selected compartments and flow of the other fluid through vother compartments, and means for rotating said valve mechanism.

9. In a heat exchange apparatus, an annular chamber, compartments in said chamber containing regenerative material having passages therethrough, a supply channel and a discharge channel for a fluid to be heated, a supply channel and a discharge channel for a fluid to be cooled, and valve mechanism for controlling flow of one fluid through said compartments in succession, and flow of the second fluid through compartments other than those through Which the first fluid is flowing, and means for moving said valve mechanism.

10. In a heat exchange apparatus, an annularchamber, compartments in said chamber containing regenerative material having passages therethrough, a supply channel and a discharge channel for a iuid to be heated, a supply channel and a discharge channel for a iiuid to be cooled, and valve mechanism for controlling ioW of one fluid through said compartments in succession, and flow of the second fluid through compartments other than those through Which the first fluid is flowing, and means mechanism.

l1. In a heat exchange apparatus, an annular chamber, compartmentsin said chamber for rotating said valve:

containing regenerative material having passaigestherethrough, a supply channel Vand a discharge channel for -a fluid tobe heated, a supply `channel and discharge channel `or a iiuid to be cooled, and valve mechanism for controlling -loW of one fluid through said compartments in succession, and flow ofthe second liuid through compartments other than those thro-ugh which the first -luid is -..,-,V0wing and in countercurrent direction, and means for moving said valve mechanism.

12. :1n 'a heat exch-ange apparatus, an-annular chamber, compartments in said chamber containing regenerative 'material having i passages therethrough, a supply channel and a disci-large channel for a Huid to be heated, a supply 'channel and a discharge channel for a flfuidqto becooled, andvalve mechanism for controllingloW-of one fiuidthrough'said ,3:0 compartments other Athan those through which thefjrst fluid is flowing and in countereurrent direction, and means for rotating said valve mechanism. Y

Y Signed by lus, this 42nd day of July, 1925.

HERBERT H. DOW. GUY H. CANNON.

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CERTIFICATE 0F CRRECTIN.

Patent No. 1,880,196. 0ct0ber 4, l1932.

HERBERT H. DOW, ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 3, line 78, claim 6, for "for rotating and" read and means for rotating said; and that the said Letters Patent should Lbe read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 9th day of October, A. D. 1934.

Leslie Frazer (Seal) Acting Commissioner of Patents. 

